Probing the Existence of a Metastable Binding Site at the β2-Adrenergic Receptor with Homobivalent Bitopic Ligands

Journal of Medicinal Chemistry
2019.0

Abstract

Herein, we report the development of bitopic ligands aimed at targeting the orthosteric binding site (OBS) and a metastable binding site (MBS) within the same receptor unit. Previous molecular dynamics studies on ligand binding to the β<sub>2</sub>-adrenergic receptor (β<sub>2</sub>AR) suggested that ligands pause at transient, less-conserved MBSs. We envisioned that MBSs can be regarded as allosteric binding sites and targeted by homobivalent bitopic ligands linking two identical pharmacophores. Such ligands were designed based on docking of the antagonist (<i>S</i>)-alprenolol into the OBS and an MBS and synthesized. Pharmacological characterization revealed ligands with similar potency and affinity, slightly increased β<sub>2</sub>/β<sub>1</sub>AR-selectivity, and/or substantially slower β<sub>2</sub>AR off-rates compared to (<i>S</i>)-alprenolol. Truncated bitopic ligands suggested the major contribution of the metastable pharmacophore to be a hydrophobic interaction with the β<sub>2</sub>AR, while the linkers alone decreased the potency of the orthosteric fragment. Altogether, the study underlines the potential of targeting MBSs for improving the pharmacological profiles of ligands.

Knowledge Graph

Similar Paper

Probing the Existence of a Metastable Binding Site at the β<sub>2</sub>-Adrenergic Receptor with Homobivalent Bitopic Ligands
Journal of Medicinal Chemistry 2019.0
Dualsteric Muscarinic Antagonists–Orthosteric Binding Pose Controls Allosteric Subtype Selectivity
Journal of Medicinal Chemistry 2014.0
Rational Design of Partial Agonists for the Muscarinic M<sub>1</sub>Acetylcholine Receptor
Journal of Medicinal Chemistry 2015.0
Further exploration of M1 allosteric agonists: Subtle structural changes abolish M1 allosteric agonism and result in pan-mAChR orthosteric antagonism
Bioorganic &amp; Medicinal Chemistry Letters 2013.0
Development of covalent antagonists for β1- and β2-adrenergic receptors
Bioorganic &amp; Medicinal Chemistry 2019.0
Fluorescent Derivatives of AC-42 To Probe Bitopic Orthosteric/Allosteric Binding Mechanisms on Muscarinic M1 Receptors
Journal of Medicinal Chemistry 2012.0
Radiolabeled Dibenzodiazepinone-Type Antagonists Give Evidence of Dualsteric Binding at the M<sub>2</sub> Muscarinic Acetylcholine Receptor
Journal of Medicinal Chemistry 2017.0
Novel Bivalent Ligands Based on the Sumanirole Pharmacophore Reveal Dopamine D<sub>2</sub> Receptor (D<sub>2</sub>R) Biased Agonism
Journal of Medicinal Chemistry 2017.0
α<sub>2</sub>-Adrenoreceptors Profile Modulation. 4. From Antagonist to Agonist Behavior
Journal of Medicinal Chemistry 2008.0
Probing the Pharmacophore for Allosteric Ligands of Muscarinic M<sub>2</sub>Receptors:  SAR and QSAR Studies in a Series of Bisquaternary Salts of Caracurine V and Related Ring Systems
Journal of Medicinal Chemistry 2004.0